Chapter 13. Tools
UnderTools, you find handy tools to troubleshoot the Telecommuting Module setup.

Packet Capture

3ComVCX IP Telecommuting Module has a built-in packet capturer which can produce pcap trace files. This
snifferwill capture all IP packets according to your selections, even those you can’t see in the log (like RTP
packets).
TheTelecommuting Module capturer needs to be manually activated and deactivated. As this produces a log which
usuallycontains a lot more packets than the standard log, it is advisable only to run the capturer for short time
periods.
Thecapture of the packets can be downloaded and analyzed in any tool that handles pcap traces, like Ethereal.

Network Interface Selection

Selecton which interface or VLAN the sniffer should listen for packets. You can also select to listen on all
interfaces.
Somenetwork cards have VLAN hardware support. For this type of cards, incoming VLAN tagged traffic is not
loggedon the main interface, but only on the VLAN interface. Outgoing VLAN tagged traffic is logged on the main
interface.
Otherinterfaces do not have VLAN hardware support. For this type of interface, VLAN traffic is logged on the
maininterface.
Currently,the only network cards in 3Com products to support VLAN are the Gigabit network cards.

IP Address Selection

Youcan limit the selection by specifying certain IP addresses.
Inthese fields, enter a single IP address (e. g., 10.3.27.3), a range of IP addresses (e. g., 10.3.27.1-10.3.28.254), an
IPaddress followed by a netmask (e. g.,10.3.27.0/24), a combination of these, or nothing at all. If a field is empty,
allIP addresses are selected.
Ifyou want to study all traffic except the one to or from a specific computer or group of computers, enter the IP
address(es)here and mark the "not this address" box.
Theselection can be modified by the control boxes under the fields A and B:
Asrc Packetsfrom the IP address in field A matches. Field B is ignored.
Adst Packetsto the IP address in field A matches. Field B is ignored.
Aany Packetsto or from the IP address in field A matches. Field B is ignored.
Ato B Packetsfrom A to B matches.
Bto A Packetsfrom B to A matches.
BetweenA&B Packetsfrom A to B, or from B to A, matches.
notthis combination Packetsthat do not match the given combination of A and B are shown in
thelog.
Ifyou, for example, want to study all packets to or from 10.3.27.18, except those to the file server 10.3.27.2, you
shouldfill in the form like this:
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